World number one Roger Federer cruised through to the quarter-finals of the Australian Open with a straight-sets win over Serbia's Novak Djokovic.
The Swiss defending champion won his match in the Rod Laver Arena in Melbourne 6-2 7-5 6-3 to set up a last-eight clash with seventh seed Tommy Robredo of Spain, who beat 18th-seeded Frenchman Richard Gasquet in four sets.
Andy Roddick overcame a stern five-set test against Mario Ancic to reach the quarter-finals on Sunday.
Roddick showed determination and character to come through a tense contest 6-3 3-6 6-1 5-7 6-4 at the Rod Laver Arena against his tough Croatian opponent.
Next up for the American, seeded sixth, is a match-up with former room-mate Mardy Fish, who beat 12th seed David Ferrer of Spain in four sets.
The American eased through the first set, but Ancic responded and claimed a crucial break in the eighth game of the second to level the contest.
Roddick hit back and cruised through the third set and was only distracted by the mis-pronunciation of his name by the French umpire.
But again Ancic responded, before Roddick sealed the epic contest in a little more than three hours in the best match of the tournament.
Fish set up the meeting with his former room-mate with a 6-1 7-6 (7-4) 2-6 7-5 victory over the 16th seed.
Tommy Haas, the 12th seed, booked his place in the fourth round with a 7-6 (7-1) 6-3 6-3 victory over fellow German Florian Mayer - while 13th seed Tomas Berdych also progressed with a comfortable 6-2 6-1 6-1 triumph over Dmitry Tursunov.
Robredo beat Gasquet 6-4 6-2 3-6 6-4 to set up his last-eight meeting with Federer.
